*{
    margin: 0;
    padding: 0;
}


body{
    height: 100vh;
    display: flex;
    /*justify-content: center;*/
    /*align-items: center;*/
}


.choose_container{
    margin-left: 55%;
    margin-top: 5%;
    /*border: 1px solid #38ada9;*/
    border-radius: 5px;
}

/* 标签栏 */
.nav{
    display: flex;
    width: 400px;
}

/*设置选项图标的大小*/
.nav .item{
    width: 200px;
    height: 90px;
    border-left: 1px solid #38ada9;
    border-top: 1px solid #38ada9;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    /* 相对定位 */
    position: relative;
    /* 溢出隐藏 */
    overflow: hidden;
}

.nav .item:last-child{
    border-right: 1px solid #38ada9;
}

/* 设置图标背景圆 */
.nav .item::before{
    content: "";
    width: 80px;
    height: 40px;
    background-color: #38ada9;
    border-radius: 10px;
    /* 绝对定位 */
    position: absolute;
    /* 过渡效果 */
    transition: 0.3s;
}

.nav .fa{
    color: #38ada9;
    position: relative;
    font-size: 36px;
}

/* 标签选中态样式 */
.nav .item.active::before{
    width: 150%;
    height: 150%;
}



/* 内容区 */
.content{
    border:1px solid #38ada9;
    width: 30%;
    height: 400px;
    position: absolute;
}

section{
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    /* 默认隐藏 */
    opacity: 0;
    /* 不透明度改变时的过渡效果 */
    transition: opacity 0.4s;
}

section span{
    font-size: 80px;
    font-weight: bold;
    color: #38ada940;
}

/* 内容区选中态样式 */
section.active{
    opacity: 1;
}
